Orthodontists, dental practitioners and medical-dental researchers are constantly searching for new and improved ways to correct the problem of constriction of the dental arches that also contribute to the overcrowding or overlapping of teeth. This condition, by narrowing of the tongue space and retraction of the tongue back to the airway, can cause the constriction of the upper airway in the retropalatal (behind the palate), retroglossal (behind the tongue) and hypoglossal (behind and below the tongue) area. As a result, the upper airway of the patient becomes constricted and causes resistance to the air passage, especially during the deeper stage of sleep when the upper airway muscles relax and cannot provide ideal support for the patency of the airway.
In the past, many different methods have been used in order to alleviate the constriction and collapse of dental arches and dental crowding. One method that has been utilized by orthodontic practitioners is that of dental expansion of the upper and lower dental arch as well as dental and or orthopedic expansion of the upper jaw in transverse direction. There have also been attempts to do so by front-to-back expansion of the dental arches by advancing the upper or lower anterior teeth forward or distalizing (retracting) the upper and lower back teeth further backward. Although the combination of these two protocols means expansion in transverse and front to back plane of space and makes more logical process, there have not been any appliance designs capable of combining these two protocols.
One dental arch expander device on the market today is a lower lingual arch to advance mandibular incisors. It does not require activation or de-activation chair side adjustments. This appliance is capable of front-to-back expansion only. As a result, it cannot expand the side to side or transverse relationship of dental arch. Another drawback of this system is that it needs to be customized for each patient (e.g., in a laboratory) and cannot be provided in a kit for a chairside use.
Another dental arch expander device that is on the market today is depicted in FIG. 1 and sometimes is referred to as the Arnold expander device. The Arnold expander device 100 develops the arch using a spring-loaded split-lingual arch housed in a tube. More specifically, the Arnold expander device 100 includes a wire 102, a spring coil 104, a tube 106, and bands 108. The spring coil 104 passes into the tube 106 to create the spring-loaded split-lingual arch. The bands 108 anchor the device 100 to the patient's molar teeth. Tension on the spring coil 104 is set before the device 100 is initially placed. Further adjustment is not usually necessary. Once the desired space has been created, the appliance can be made passive by carefully pinching the tube 106 tight against the wire 102 with a pair of heavy wire cutters or tube crimping pliers. This device 100 is not capable of advancing the dental arches from back to front or distalizing the back teeth.